21177079 has 8 divisors (see below), whose sum is σ = 26402688. Its totient is φ = 16501560.

The previous prime is 21177071. The next prime is 21177083. The reversal of 21177079 is 97077112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21177079 - 2³ = 21177071 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21177071) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 137437 + ... + 137590.

It is an arithmetic number, because the mean of its divisors is an integer number (3300336).

Almost surely, 2^21177079 is an apocalyptic number.

21177079 is a deficient number, since it is larger than the sum of its proper divisors (5225609).

21177079 is a wasteful number, since it uses less digits than its factorization.

21177079 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 275045.

The product of its (nonzero) digits is 6174, while the sum is 34.

The square root of 21177079 is about 4601.8560386001. The cubic root of 21177079 is about 276.6657203884.

The spelling of 21177079 in words is "twenty-one million, one hundred seventy-seven thousand, seventy-nine".